as clear as mud

(informal)not at all easy to understand

(非正式)难以弄清楚

drag someone through the mud

slander or denigrate someone publicly

玷污，诋毁

here's mud in your eye!

(Brit. informal)used to express friendly feelings towards one's companions before drinking

(英，非正式)干杯！祝您健康!

one's name is mud

(informal)one is in disgrace or unpopular

(非正式)某人名声扫地了；某人失宠倒霉了

if you forget their birthdays your name is mud.

如果你忘记了他们的生日，那就够你受的了。